The semi-automatic assault rifle of choice

The last time there was a mass shooting at a school in the United States when an AR-15 semi-automatic rifle was used, I had very faint hopes that possibly someone somewhere with reasonable authority, such as a Congressman or a state governor or even the president might come to the conclusion that allowing American citizens, of whatever age, to walk into a shop and buy one of these deadly assault rifles should be STOPPED. But no one stepped forward. There was the usual talk about how banning guns was not the issue. An argument that I have never understood. Surely if there weren't shops selling military-style weapons over the counter, the shooting massacres at schools and churches and other public places would not happen any longer? I would have thought that sort of logic was unassailable. But no, the argument was still, "Ah but it's not the guns that kill people, it's the men/women/children pressing the trigger that kills people"! Well ok, even if we stick with that ridiculous answer, how come someone who has written on his social media stuff that he wants to do a shooting at a school is able to get his hands on this appalling weapon, the AR-15 rifle? The alleged shooter at the school in Parkland, Florida, had done just that and the FBI had even been tipped off. Yet this person walks to his former school, opens fire at anyone he spots and then calmly progresses into the school and continues shooting. With a high-powered semi-automatic rifle in your hands it's so easy. So, biq question for the day: will anyone now step forward and say: "AR-15 semi-automatic rifles are now prohibited, they are never to be sold to any civilian ever again." This won't end shootings in the future but it just might make a big difference. Will anyone do this? No they won't. So how long do we have to wait before the next school massacre? Three months?